A series of new poly(arylene ether phenyl-s-triazine)s was prepared by the nucleophilic aromatic substitution polymerization of the potassium salt of bisphenols with 2,4-bis(halophenyl)-6-phenyl-s-triazine in N-methyl-2-pyrrolidone at elevated temperature. The polymers with inherent viscosities exceeding 0.5 were obtained after polymerization for 1 h using 2,4-bis (fluorophenyl)-6-phenyl-s-triazine as a monomer. The glass transition temperatures of the resulting polymers ranged from 200 to 260-degrees-C depending on the bisphenol used in the polymer synthesis. The poly (arylene ether phenyl-s-triazine)s demonstrated excellent thermal stabilities in excess of 490-degrees-C (5% weight loss in air). The isothermal TGA measurements (400-degrees-C under air or nitrogen atmosphere) revealed that the 4,4’-biphenol- and hydroquinone-based poly (arylene ether phenyl-s-triazine) s belong to the most superior class of heat resistant polymers, such as polyimide Kapton(TM). The mechanical properties of these polymers are also described.